The Active Earth Pressure Research Of Considering The Retaining Wall Movement Mode And Movement Value

More and more people have been paid more attention to calculate the earth pressure on retaining wall. At present, Coulomb’s theory of earth pressure and Rankine’s theory of earth pressure have been widely used to calculate the earth pressure on retaining wall, but the two theories are used under certain assumptions. It will often lead to erroneous results when the two theories are applied to the practical engineering. First, the Coulomb’s theory thinks that the retaining wall is at a uniform translation state to reach the limiting state. Actually, it is not practical. Because there are many movements of retaining wall in the practical engineering. The second, the Coulomb’s theory is not accurate that it uses the balance equation under the static equilibrium to calculate the earth pressure when the backfill of the wall reaches the limiting state. However, the backfill of the wall can not reach the limiting state on real significance, so the earth pressure which is caculated by Coulomb’s theory is less than the actual value. The third, the Coulomb’s theory is also not accurate that it describes the backfill as a whole, and ignores the change of the stress of the soil under the actual situation in their own. However, Rankine’s theory is improved compare to the Coulomb’s theory, and considering the stress changes in the soil itself, but it is not accurate that it ignores the frictional resistance between retaining wall and filling interface. So, in order to strengthen the rationality of retaining wall design in some real cases, we need to consider the various factors which can influence the changes of earth pressure.The objection of the thesis is based on many scholars’ research and the changes of wall movement and mode of rotation about retaining wall which influence on the active earth pressure. The article uses the rigid retaining wall as an example, and thinks that it will appear three movement modes named Rotation about base(RB),Rotation about top(RT),Translation(T).It defines that the retaining wall moves from the initial stationary state to the limiting active state as “the intermediate state”, called the non-limit active state. That retaining wall in the process of filling deviate from the mobile, the filled soil friction angel appears gradually with the increase of the wall displacement. And introduce the concept of friction angle play value, to establish the relationship between the friction angle and displacement. At the same time, the active earth pressure behind the retaining wall decreases gradually from at-rest earth pressure as the increase of wall displacement, and tends to be the limit active earth pressure slowly. At this time, based on the relationship between the friction angle and wall displacement, the active earth pressure under non-limit state has been calculated. Finally, by using this method, for the rigid retaining wall at different movement modes and movement values, the unit earth pressure, the resultant force of earth pressure and the acting point of the resultant force under non-limit state are obtained. In addition, comparing the results of this paper method with the results of the linear theory of Chang obtains that the calculation method of this paper is more accurate than the theory of Chang, and using it in the design of retaining wall will be more and more reasonable and scientific.